diff --git a/lib/searchkick.rb b/lib/searchkick.rb
index 16457ca..d316e90 100644
--- a/lib/searchkick.rb
+++ b/lib/searchkick.rb
@@ -88,7 +88,7 @@ module Searchkick
     @server_below7
   end
 
-  def self.search(term = "*", model: nil, relation: false, **options, &block)
+  def self.search(term = "*", model: nil, relation: nil, **options, &block)
     options = options.dup
     klass = model
 
diff --git a/lib/searchkick/relation.rb b/lib/searchkick/relation.rb
index be9fde6..cb22dac 100644
--- a/lib/searchkick/relation.rb
+++ b/lib/searchkick/relation.rb
@@ -381,6 +381,15 @@ module Searchkick
       self
     end
 
+    def conversions_term(value)
+      spawn.conversions_term!(value)
+    end
+
+    def conversions_term!(value)
+      options[:conversions_term] = value
+      self
+    end
+
     # same as Active Record
     def inspect
       entries = results.first(11).map!(&:inspect)
diff --git a/test/boost_test.rb b/test/boost_test.rb
index 8cc4df8..cc372e5 100644
--- a/test/boost_test.rb
+++ b/test/boost_test.rb
@@ -39,6 +39,7 @@ class BoostTest < Minitest::Test
 
     assert_order "speaker", ["Speaker A", "Speaker B", "Speaker C", "Speaker D"], {conversions: "conversions_a"}, Speaker
     assert_order "speaker", ["Speaker D", "Speaker C", "Speaker B", "Speaker A"], {conversions: "conversions_a", conversions_term: "speaker_1"}, Speaker
+    assert_order_relation ["Speaker D", "Speaker C", "Speaker B", "Speaker A"], Speaker.search("speaker", relation: true).conversions(:conversions_a).conversions_term("speaker_1")
   end
 
   def test_conversions_case
--
libgit2 0.21.0